<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../vue.js"></script>
</head>

<body>
    <div id="app">
        <h1>{{isHot?"热啊":"冻啊"}}</h1>
        <button @click="isHot = !isHot">change</button>
    </div>
    <script>
        const vm = new Vue({
            el: '#app',
            data() {
                return {
                    isHot: true,
                }
            },
            watch: {
                //如果没有深度监听和立即监听,可以直接使用watch的简写
                isHot() {
                    console.log('改变天气了');
                }
            }
        })
    </script>
</body>

</html>